Rear support slide for mowing knife heads



Aug. 20, 1957 I A. N. SIMPSON 2,803,104

REAR SUPPORT SLIDE FOR MOWING KNIFE HEADS Filed Aug. 12, 1955 INVENTQR. .41. v4 N. SIMPSON,

ATTORNEYS;

REAR SUPPORT SLIDE FOR MOWING KNIFE HEADS Alva N. Simpson, Ogallala, Nebr.

Application AugustlZ, 1955, Serial No. 527,955

3 Claims. (Cl. 56-603) This invention relates to mowing machines, and more particularly has reference to a rear support slide or bearing for the head of the knife or sickle bar of a machine in which said knife reciprocates upon a stationary finger bar.

Conventionally, the support slide or hearing of a knife head, in a machine of the type referred to, lies substantially in the horizontal plane of the knife head itself, has only approximately of an inch of wear surface, and opens upwardly in such a manner that dirt feeds thereinto during operation of the mowing machine, at a relatively high rate.

As a result, due to the relatively small amount of surface which must take the wear, and due, further, to the fact that the construction is such that dirt enters the slide assembly or bearing of the knife head at a rapid rate, wear occurs with great rapidity. Therefore, the knife head, and hence the entire cutter or knife bar secured thereto, becomes subject to deviation out of its assigned plane relative to the finger bar during the reciprocating movement of the cutter bar, so that the cutter bar moves out of shear, in turn causing wear of the cutter bar knife sections or blades, the guard fingers across said blades are reciprocated, and the ledger plates underlying said knife sections or cutter blades. Frequent replacement of the cutter blades, knife sections, and ledger plates is required, at great expense, and apart from this, it is difficult to maintain, during the normal operation of the machine, a proper shearing action between the reciprocating and stationary bar assemblies of the structure.

The main object of the present invention is to eliminate the deficiencies in conventional mowing machine construction noted above, and to this end, the invention, summarized briefly, comprises a rear support slide or bearing assembly for the knife head of the cutter bar, so designed that the slide is transversely inclined at an angle of approximately 20 degrees from the horizontal, more or less, with said slide being disposed, in a preferred embodiment, a full inch above those of conventional mowing machine constructions. Further, in accordance with the invention, the rear support of the knife head is increased as regards the area of the wearing surface thereof in such a manner that said wear surface is approximately three times as wide as that which has heretofore been provided. The knife head, to accommodate the same to the support slide bearing therefor, is formed with a rearwardly projecting, inclined extension or ear slidably engaged between upper and lower, removable wear plates mounted upon the support with said inclined extension being connected to the body of the knife head by a relatively low, vertical wall spaced closely from the means conventionally provided upon the knife headfor connecting the same to a driving linkage.

Among more specific objects of the invention are the following:

First, to provide a substantial, strong, and lasting rear support for the sickle or knife head, that will add greatly to support for the knife head, in conventionally design-ed mowing machines with a minimum of modification of the mowing machine design;

Fourth, to facilitate the replacement of the wearreceiving portions of the rear support for the knife head, at a minimum of cost;

Fifth, to so support the knife head at the rear thereof as to impart a characteristic to the invention wherein the knife head will be held at a correct level at all times, so that, in view of the rigid connection of the sickle to the head and the stiffness of the sickle, there is maintained a correct shearing relationship between the sickle knives and ledger plates, regardless of wear that may exist be tween the rear surface of the sickle and its supporting wear plates, all this being the end result of a particularly efiicient rear support of the knife head;

Sixth, to so design the rear support for the knife head as to exclude dirt and other foreign matter, thus to still further reduce wear of the parts; and

Seventh, to provide for a greatly increased amount of wearing surface for the slide, while at the same time extending rearwardly the point at which wearing pressure is directed against the parts, in a manner to cause a given amount 'of wear to result in only a fraction of the disaligning effects on the shearing parts involved in conventional mowing machine constructions.

Other objects will appear from the following description, the claims appended thereto, and from the annexed drawing, in which like reference characters designate like parts throughout the several views, and wherein:

Figure 1 is a fragmentary perspective view of a mowing machine cutting assembly, in which has been incorporated the rear knife head support constituting the present invention; and

Figure 2 is an enlarged transverse sectional view on line 22 of Figure l.

The reference numeral 10 generally designates a guard shoe at one end of a mowing machine assembly, said shoe being of wholly conventional construction and not constituting, per se, part of the present invention. The shoe, as is usual, is provided intermediate its ends with an upwardly opening, shallow recess 12, and this in turn merges into a shallow, upwardly opening recess 14 at the rear end portion of the shoe, lying in a horizontal plane just below that of the recess 12 as shown in Fig ure 2.

At 16 there has been designated the finger bar of the cutter assembly, fixedly secured to the shoe within the recess 14, and provided, at uniformly spaced locations along its length, with forwardly projecting guard fingers 18.

The reference numeral 26 has been applied to the cutter, head or knife head of the machine, this being secured fixedly to one end of the knife bar, having the side by side knife sections or cutter blades 22 reciprocating within provided recesses of the guard fingers 18. Secured to and projecting upwardly from the upper end of the knife head is a means for connecting a reciprocating cutter bar of which the knife head is a part, to a driving assembly adapted to impart reciprocating motion to the knife bar relative to the finger bar and shoe 10. Said means includes an upstanding plate rigid with the knife head, having a ball, element 24 formed thereon.

'Integrally formed upon the outer end portion of the knife head is a forwardly projecting extension 26 (Figure 2) slidably engaged in recess 12, and holding the extension in place within the recess is a clip 28 having openings receiving upstanding studs provided upon the shoe, nuts 30 being threaded upon said studs against the clip to hold the same in place.

All this is conventional construction and does not per se constitute part of the present invention.

Ordinarily, the rear support or bearing for the knife head is disposed in a horizontal plane substantially common to that of the body of the knife head and of the extension 26. Further, said rear support is fully open in an upward direction, and hence, foreign matter, dirt, etc. freely enters the same, causing rapid wear of the rear support, resulting in speedy misalignment of the cutter bar relative to the finger bar, resulting replacement of the cutter blades, guard fingers, ledger plates, etc. Further, the rear support is relatively narrow in width, being usually no more than /8 of an inch, so that all the wear must be taken upon a relatively small area still further accelerating wear or breakage of the relatively movable parts of the cutter bar assembly.

In accordance with the present invention, instead of the conventional rear support, there is provided a support frame 32 secured by bolts 34 to the stationary finger bar 16, immediately in back of the ball element 24, and this frame is formed with a top wall 36 of substantial width, inclined at approximately 20 degrees from the horizontal, more or less. The top wall 36 is integrally formed with a rear extension 38, further increasing the overall width of the top wall, and supported upon and overlying the full area of the top wall and extension is a lower wear plate 40.

Supported upon the rear edge portion of the lower wear plate, and extending the full length of said lower wear plate, is a spacer bar 42, and upon the spacer bar there is supported an upper wear plate 44 having its several edges in registration with the edges of the lower wear plate. As a result, there is defined a forwardly opening, inclined, slide-receiving recess 45 in the rear support, between the lower and upper wear plates, said recess being closed at its back by the spacer 42.

Fixedly connecting the extension 38, lower wear plate spacer 42, and upper wear plate 44 is a pair of bolts 46, spaced longitudinally of the rear support, and it will be seen that by removal of said bolts, either of the wear plates, as well as the spacer, can be individually replaced at very low expense and with a minimum amount of difficulty.

Integrally formed upon the rear edge of the knife head 20 is a low, upwardly projecting, elongated connecting wall 48, merging at its upper edge into a rearwardly, upwardly inclined slide 50. The inclination of slide 50 corresponds to that of the slide-receiving recess and rear support, and the slide is of substantial width, being approximately three times as great in width as the conventional rear support wear surface of mowing machines in present day use.

Further, it is to be noted that the slide is disposed at a level a substantial distance above the horizontal plane of the knife head proper, and this particular arrangement has been found to impart a characteristic to the knife head wherein the knife head will remain in its assigned plane, during the reciprocating motion thereof, for a particularly long period of time, without substantial deviation to an extent as would tend to cause wear of the relatively reciprocating knife and finger bar components.

By reason of the arrangement illustrated and described, even a mower which has been badly worn on the surfaces of the reciprocating knife blade and of guard finger components, operates with substantially full shearing efficiency as the knife head is held in its correct level, and the construction for the knife head rear support illustrated and described has been found to accomplish this highly desirable result. Eflicient operation of the mowing machine, resulting in the cutting of a clean swath at all times, thus is provided by reason of the arrangement. This, it has been found, i due to the fact that the stiffness with which the sickle bar knife head is held by the illustrated rear support maintains a proper shearing action regardless of wear of the cutting arts.

p Apart from the above, the rear support itself is kept from wearing, due to the inclination of the parts in a direction that will cause foreign matter to be almost completely excluded, and still further, the greatly increased amount of wearing surface and the disposition of the wear pressure a substantial distance rearwardly from the cutter bar reduces the misaligning effect on the knife head to a minimum, so that a given amount of wear produces only a fraction of the misalignment which has heretofore been caused.

The reason why these desirable results are achieved, are believed grounded basically in the proper formation of a rear support for the knife head, illustrated and described herein, which formation holds and maintains the knife bar in its fully correct relationship to the guard plates of the machine, over a particularly long amount of time.

Still further, the construction is possessed of the highly desirable characteristic wherein the only points of wear upon the rear support are the upper and lower wear plates, and the spacer, and since these are low cost, readily available components, repair and maintenance of the rear support is achieved at very low cost.

It is believed apparent that the invention is not necessarily confined to the specific use or uses thereof described above, since it may be utilized for any purpose to which it may be suited. Nor is the invention to be necessarily limited to the specific construction illustrated and described, since such construction is only intended to be illustrative of the principles, it being considered that the invention comprehends any minor change in construction that may be permitted within the scope of the appended claims.

What is claimed is:

1. In a mowing machine the combination, with a knife head and a finger bar on which the knife head is reciprocably mounted, of: a support frame stationarily mounted on said finger bar and having an inclined top surface, said frame including a rearwardly projecting, inclined extension constituting a rearwardly projecting prolongation of said top surface; a lower wear plate supported upon said top surface; a spacer bar overlying the rear edge portion of the lower plate; an upper wear plate overlying said spacer bar and cooperating with the lower wear plate and spacer bar in defining a forwardly opening recess; means removably and fixedly connecting said extension of the frame, lower wear plate, spacer, and upper wear plate; and a slide rigid with and projecting rearwardly from said head, said slide being inclined from the horizontal correspondingly to the top surface of said frame and being slidably engaged in said recess.

2. In a mowing machine the combination, with a knife head and a finger bar on which the knife head is reciprocably mounted, of: a support frame stationarily mounted on said finger bar and having an inclined top surface, said frame including a rearwardly projecting, inclined extension constituting a rearwardly projecting prolongation of said top surface; a lower wear plate supported upon said top surface; a spacer bar overlying the rear edge portion of the lower plate; an upper wear plate overlying said spacer bar and cooperating with the lower wear plate and spacer bar in defining a forwardly opening recess; means removably and fixedly connecting said extension of the frame, lower wear plate, spacer, and upper wear plate; and a slide rigid with and projecting rearwardly from said head, said slide being inclined from the horizontal correspondingly to the top surface of said frame and being slidably engaged in said recess, said recess being spaced above the finger bar and knife head a substantial distance, the slide at its forward end being integrally formed with a low, vertical connecting wall rigidly mounted upon the rear edge of said knife head.

3. In a mowing machine the combination, with a knife head and finger bar on which the knife head is reciprocably mounted, said finger bar having a fiat, wide surfacein back of the knife head in the sense of direction of forward movement of the mowing machine, of: a support frame stationarily mounted on said surface of the finger bar, said frame being spaced rearwardly from the back edge of the knife head and having a top surfac inclined from the horizontal, the knife head reciprocating in a horizontal plane and said surface of the frame being spaced upwardly from said plane over the entire area of said inclined surface; upper and lower wear plates removably, fixedly connected to the frame in position overlying said surface, said plates being spaced apart to define therebetween a recess, the plates being of substantial width to define a recess of correspondingly substantial depth, the recess opening forwardly, downwardly toward the knife head and being disposed wholly above the plane of reciprocating movement of the knife head; a low, vertical wall fixedly secured to and projecting upwardly from the back edge of the knife head; and a flat, wide slide plate rigid with and extending rearwardly, upwardly from the vertical wall, said slide plate being extended into the recess with the top and bottom surfaces of the slide plate in slidable contact with the upper and lower wear plates respectively, the slide plate being disposed wholly rearwardly, upwardly from the back edge of the knife head and being inclined from the horizontal correspondingly to the top surface of the frame.

References Cited in the file of this patent UNITED STATES PATENTS 286,603 Gause Oct. 16, 1883 2,621,521 Lewis et al. Dec. 16, 1952 2,737,006 Klingler Mar. 6, 1956 FOREIGN PATENTS 288,647 Switzerland Feb. 15, 1953 

